改善石英晶体旋光滤波器次极大的优化设计

Optimal design of sideband energy of a rotatory quartz filter

为了改善滤波光谱的次极大,提高透过滤波片观察像的衬度,设计了减小次极大光强的石英晶体旋光滤波结构,并从理论上分析了滤波特性。以3级石英晶体旋光滤波器为例,由分析可知,在第3级之后增加1级与第1级或第2级相同的结构,均有效地减小了次极大的光强;比较发现,增加1级第2级的结构效果较好。结果表明,此设计对改善石英晶旋光滤波器次极大应用于观测光谱中提供了理论依据。

In order to reduce sideband spectral energy and improve image lining of a quartz filter, a novel filter structure was designed and its characteristics were analyzed theoretically. Taking a three-level quartz filter for example,its sideband energy can be reduced efficiently by adding the same structure as the first or second level after the third level Comparatively speaking, it is better to add a structure the same as the second level. The outcome provides academic gist to reduce sideband energy in spectral observation.